When a node of the treeview (in a combobox) is clicked, the text and value of this node is set to the selected item of the combobox. client side this works well. serverside the selectedvalue is rondomly empty.
function nodeClicking(sender, args) {
var comboBox = $find("<%= cbEmployees.ClientID %>");
var node = args.get_node()
comboBox.set_text(node.get_text());
comboBox.trackChanges();
var item = comboBox.get_items().getItem(0);
item.set_value(node.get_value());
item.set_text(node.get_text());
comboBox.commitChanges();
comboBox.hideDropDown();
comboBox.attachDropDown();
}